--- /dev/null
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imports
+
+import (
+ "bytes"
+ "context"
+ "encoding/json"
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "io/ioutil"
+ "os"
+ "path"
+ "path/filepath"
+ "reflect"
+ "sort"
+ "strconv"
+ "strings"
+ "sync"
+ "unicode"
+ "unicode/utf8"
+
+ "golang.org/x/tools/go/ast/astutil"
+ "golang.org/x/tools/internal/gocommand"
+ "golang.org/x/tools/internal/gopathwalk"
+)
+
+// importToGroup is a list of functions which map from an import path to
+// a group number.
+var importToGroup = []func(localPrefix, importPath string) (num int, ok bool){
+ func(localPrefix, importPath string) (num int, ok bool) {
+ if localPrefix == "" {
+ return
+ }
+ for _, p := range strings.Split(localPrefix, ",") {
+ if strings.HasPrefix(importPath, p) || strings.TrimSuffix(p, "/") == importPath {
+ return 3, true
+ }
+ }
+ return
+ },
+ func(_, importPath string) (num int, ok bool) {
+ if strings.HasPrefix(importPath, "appengine") {
+ return 2, true
+ }
+ return
+ },
+ func(_, importPath string) (num int, ok bool) {
+ firstComponent := strings.Split(importPath, "/")[0]
+ if strings.Contains(firstComponent, ".") {
+ return 1, true
+ }
+ return
+ },
+}
+
+func importGroup(localPrefix, importPath string) int {
+ for _, fn := range importToGroup {
+ if n, ok := fn(localPrefix, importPath); ok {
+ return n
+ }
+ }
+ return 0
+}
+
+type ImportFixType int
+
+const (
+ AddImport ImportFixType = iota
+ DeleteImport
+ SetImportName
+)
+
+type ImportFix struct {
+ // StmtInfo represents the import statement this fix will add, remove, or change.
+ StmtInfo ImportInfo
+ // IdentName is the identifier that this fix will add or remove.
+ IdentName string
+ // FixType is the type of fix this is (AddImport, DeleteImport, SetImportName).
+ FixType ImportFixType
+ Relevance float64 // see pkg
+}
+
+// An ImportInfo represents a single import statement.
+type ImportInfo struct {
+ ImportPath string // import path, e.g. "crypto/rand".
+ Name string // import name, e.g. "crand", or "" if none.
+}
+
+// A packageInfo represents what's known about a package.
+type packageInfo struct {
+ name string // real package name, if known.
+ exports map[string]bool // known exports.
+}
+
+// parseOtherFiles parses all the Go files in srcDir except filename, including
+// test files if filename looks like a test.
+func parseOtherFiles(fset *token.FileSet, srcDir, filename string) []*ast.File {
+ // This could use go/packages but it doesn't buy much, and it fails
+ // with https://golang.org/issue/26296 in LoadFiles mode in some cases.
+ considerTests := strings.HasSuffix(filename, "_test.go")
+
+ fileBase := filepath.Base(filename)
+ packageFileInfos, err := ioutil.ReadDir(srcDir)
+ if err != nil {
+ return nil
+ }
+
+ var files []*ast.File
+ for _, fi := range packageFileInfos {
+ if fi.Name() == fileBase || !strings.HasSuffix(fi.Name(), ".go") {
+ continue
+ }
+ if !considerTests && strings.HasSuffix(fi.Name(), "_test.go") {
+ continue
+ }
+
+ f, err := parser.ParseFile(fset, filepath.Join(srcDir, fi.Name()), nil, 0)
+ if err != nil {
+ continue
+ }
+
+ files = append(files, f)
+ }
+
+ return files
+}
+
+// addGlobals puts the names of package vars into the provided map.
+func addGlobals(f *ast.File, globals map[string]bool) {
+ for _, decl := range f.Decls {
+ genDecl, ok := decl.(*ast.GenDecl)
+ if !ok {
+ continue
+ }
+
+ for _, spec := range genDecl.Specs {
+ valueSpec, ok := spec.(*ast.ValueSpec)
+ if !ok {
+ continue
+ }
+ globals[valueSpec.Names[0].Name] = true
+ }
+ }
+}
+
+// collectReferences builds a map of selector expressions, from
+// left hand side (X) to a set of right hand sides (Sel).
+func collectReferences(f *ast.File) references {
+ refs := references{}
+
+ var visitor visitFn
+ visitor = func(node ast.Node) ast.Visitor {
+ if node == nil {
+ return visitor
+ }
+ switch v := node.(type) {
+ case *ast.SelectorExpr:
+ xident, ok := v.X.(*ast.Ident)
+ if !ok {
+ break
+ }
+ if xident.Obj != nil {
+ // If the parser can resolve it, it's not a package ref.
+ break
+ }
+ if !ast.IsExported(v.Sel.Name) {
+ // Whatever this is, it's not exported from a package.
+ break
+ }
+ pkgName := xident.Name
+ r := refs[pkgName]
+ if r == nil {
+ r = make(map[string]bool)
+ refs[pkgName] = r
+ }
+ r[v.Sel.Name] = true
+ }
+ return visitor
+ }
+ ast.Walk(visitor, f)
+ return refs
+}
+
+// collectImports returns all the imports in f.
+// Unnamed imports (., _) and "C" are ignored.
+func collectImports(f *ast.File) []*ImportInfo {
+ var imports []*ImportInfo
+ for _, imp := range f.Imports {
+ var name string
+ if imp.Name != nil {
+ name = imp.Name.Name
+ }
+ if imp.Path.Value == `"C"` || name == "_" || name == "." {
+ continue
+ }
+ path := strings.Trim(imp.Path.Value, `"`)
+ imports = append(imports, &ImportInfo{
+ Name: name,
+ ImportPath: path,
+ })
+ }
+ return imports
+}
+
+// findMissingImport searches pass's candidates for an import that provides
+// pkg, containing all of syms.
+func (p *pass) findMissingImport(pkg string, syms map[string]bool) *ImportInfo {
+ for _, candidate := range p.candidates {
+ pkgInfo, ok := p.knownPackages[candidate.ImportPath]
+ if !ok {
+ continue
+ }
+ if p.importIdentifier(candidate) != pkg {
+ continue
+ }
+
+ allFound := true
+ for right := range syms {
+ if !pkgInfo.exports[right] {
+ allFound = false
+ break
+ }
+ }
+
+ if allFound {
+ return candidate
+ }
+ }
+ return nil
+}
+
+// references is set of references found in a Go file. The first map key is the
+// left hand side of a selector expression, the second key is the right hand
+// side, and the value should always be true.
+type references map[string]map[string]bool
+
+// A pass contains all the inputs and state necessary to fix a file's imports.
+// It can be modified in some ways during use; see comments below.
+type pass struct {
+ // Inputs. These must be set before a call to load, and not modified after.
+ fset *token.FileSet // fset used to parse f and its siblings.
+ f *ast.File // the file being fixed.
+ srcDir string // the directory containing f.
+ env *ProcessEnv // the environment to use for go commands, etc.
+ loadRealPackageNames bool // if true, load package names from disk rather than guessing them.
+ otherFiles []*ast.File // sibling files.
+
+ // Intermediate state, generated by load.
+ existingImports map[string]*ImportInfo
+ allRefs references
+ missingRefs references
+
+ // Inputs to fix. These can be augmented between successive fix calls.
+ lastTry bool // indicates that this is the last call and fix should clean up as best it can.
+ candidates []*ImportInfo // candidate imports in priority order.
+ knownPackages map[string]*packageInfo // information about all known packages.
+}
+
+// loadPackageNames saves the package names for everything referenced by imports.
+func (p *pass) loadPackageNames(imports []*ImportInfo) error {
+ if p.env.Logf != nil {
+ p.env.Logf("loading package names for %v packages", len(imports))
+ defer func() {
+ p.env.Logf("done loading package names for %v packages", len(imports))
+ }()
+ }
+ var unknown []string
+ for _, imp := range imports {
+ if _, ok := p.knownPackages[imp.ImportPath]; ok {
+ continue
+ }
+ unknown = append(unknown, imp.ImportPath)
+ }
+
+ resolver, err := p.env.GetResolver()
+ if err != nil {
+ return err
+ }
+
+ names, err := resolver.loadPackageNames(unknown, p.srcDir)
+ if err != nil {
+ return err
+ }
+
+ for path, name := range names {
+ p.knownPackages[path] = &packageInfo{
+ name: name,
+ exports: map[string]bool{},
+ }
+ }
+ return nil
+}
+
+// importIdentifier returns the identifier that imp will introduce. It will
+// guess if the package name has not been loaded, e.g. because the source
+// is not available.
+func (p *pass) importIdentifier(imp *ImportInfo) string {
+ if imp.Name != "" {
+ return imp.Name
+ }
+ known := p.knownPackages[imp.ImportPath]
+ if known != nil && known.name != "" {
+ return known.name
+ }
+ return ImportPathToAssumedName(imp.ImportPath)
+}
+
+// load reads in everything necessary to run a pass, and reports whether the
+// file already has all the imports it needs. It fills in p.missingRefs with the
+// file's missing symbols, if any, or removes unused imports if not.
+func (p *pass) load() ([]*ImportFix, bool) {
+ p.knownPackages = map[string]*packageInfo{}
+ p.missingRefs = references{}
+ p.existingImports = map[string]*ImportInfo{}
+
+ // Load basic information about the file in question.
+ p.allRefs = collectReferences(p.f)
+
+ // Load stuff from other files in the same package:
+ // global variables so we know they don't need resolving, and imports
+ // that we might want to mimic.
+ globals := map[string]bool{}
+ for _, otherFile := range p.otherFiles {
+ // Don't load globals from files that are in the same directory
+ // but a different package. Using them to suggest imports is OK.
+ if p.f.Name.Name == otherFile.Name.Name {
+ addGlobals(otherFile, globals)
+ }
+ p.candidates = append(p.candidates, collectImports(otherFile)...)
+ }
+
+ // Resolve all the import paths we've seen to package names, and store
+ // f's imports by the identifier they introduce.
+ imports := collectImports(p.f)
+ if p.loadRealPackageNames {
+ err := p.loadPackageNames(append(imports, p.candidates...))
+ if err != nil {
+ if p.env.Logf != nil {
+ p.env.Logf("loading package names: %v", err)
+ }
+ return nil, false
+ }
+ }
+ for _, imp := range imports {
+ p.existingImports[p.importIdentifier(imp)] = imp
+ }
+
+ // Find missing references.
+ for left, rights := range p.allRefs {
+ if globals[left] {
+ continue
+ }
+ _, ok := p.existingImports[left]
+ if !ok {
+ p.missingRefs[left] = rights
+ continue
+ }
+ }
+ if len(p.missingRefs) != 0 {
+ return nil, false
+ }
+
+ return p.fix()
+}
+
+// fix attempts to satisfy missing imports using p.candidates. If it finds
+// everything, or if p.lastTry is true, it updates fixes to add the imports it found,
+// delete anything unused, and update import names, and returns true.
+func (p *pass) fix() ([]*ImportFix, bool) {
+ // Find missing imports.
+ var selected []*ImportInfo
+ for left, rights := range p.missingRefs {
+ if imp := p.findMissingImport(left, rights); imp != nil {
+ selected = append(selected, imp)
+ }
+ }
+
+ if !p.lastTry && len(selected) != len(p.missingRefs) {
+ return nil, false
+ }
+
+ // Found everything, or giving up. Add the new imports and remove any unused.
+ var fixes []*ImportFix
+ for _, imp := range p.existingImports {
+ // We deliberately ignore globals here, because we can't be sure
+ // they're in the same package. People do things like put multiple
+ // main packages in the same directory, and we don't want to
+ // remove imports if they happen to have the same name as a var in
+ // a different package.
+ if _, ok := p.allRefs[p.importIdentifier(imp)]; !ok {
+ fixes = append(fixes, &ImportFix{
+ StmtInfo: *imp,
+ IdentName: p.importIdentifier(imp),
+ FixType: DeleteImport,
+ })
+ continue
+ }
+
+ // An existing import may need to update its import name to be correct.
+ if name := p.importSpecName(imp); name != imp.Name {
+ fixes = append(fixes, &ImportFix{
+ StmtInfo: ImportInfo{
+ Name: name,
+ ImportPath: imp.ImportPath,
+ },
+ IdentName: p.importIdentifier(imp),
+ FixType: SetImportName,
+ })
+ }
+ }
+
+ for _, imp := range selected {
+ fixes = append(fixes, &ImportFix{
+ StmtInfo: ImportInfo{
+ Name: p.importSpecName(imp),
+ ImportPath: imp.ImportPath,
+ },
+ IdentName: p.importIdentifier(imp),
+ FixType: AddImport,
+ })
+ }
+
+ return fixes, true
+}
+
+// importSpecName gets the import name of imp in the import spec.
+//
+// When the import identifier matches the assumed import name, the import name does
+// not appear in the import spec.
+func (p *pass) importSpecName(imp *ImportInfo) string {
+ // If we did not load the real package names, or the name is already set,
+ // we just return the existing name.
+ if !p.loadRealPackageNames || imp.Name != "" {
+ return imp.Name
+ }
+
+ ident := p.importIdentifier(imp)
+ if ident == ImportPathToAssumedName(imp.ImportPath) {
+ return "" // ident not needed since the assumed and real names are the same.
+ }
+ return ident
+}
+
+// apply will perform the fixes on f in order.
+func apply(fset *token.FileSet, f *ast.File, fixes []*ImportFix) {
+ for _, fix := range fixes {
+ switch fix.FixType {
+ case DeleteImport:
+ astutil.DeleteNamedImport(fset, f, fix.StmtInfo.Name, fix.StmtInfo.ImportPath)
+ case AddImport:
+ astutil.AddNamedImport(fset, f, fix.StmtInfo.Name, fix.StmtInfo.ImportPath)
+ case SetImportName:
+ // Find the matching import path and change the name.
+ for _, spec := range f.Imports {
+ path := strings.Trim(spec.Path.Value, `"`)
+ if path == fix.StmtInfo.ImportPath {
+ spec.Name = &ast.Ident{
+ Name: fix.StmtInfo.Name,
+ NamePos: spec.Pos(),
+ }
+ }
+ }
+ }
+ }
+}
+
+// assumeSiblingImportsValid assumes that siblings' use of packages is valid,
+// adding the exports they use.
+func (p *pass) assumeSiblingImportsValid() {
+ for _, f := range p.otherFiles {
+ refs := collectReferences(f)
+ imports := collectImports(f)
+ importsByName := map[string]*ImportInfo{}
+ for _, imp := range imports {
+ importsByName[p.importIdentifier(imp)] = imp
+ }
+ for left, rights := range refs {
+ if imp, ok := importsByName[left]; ok {
+ if m, ok := stdlib[imp.ImportPath]; ok {
+ // We have the stdlib in memory; no need to guess.
+ rights = copyExports(m)
+ }
+ p.addCandidate(imp, &packageInfo{
+ // no name; we already know it.
+ exports: rights,
+ })
+ }
+ }
+ }
+}
+
+// addCandidate adds a candidate import to p, and merges in the information
+// in pkg.
+func (p *pass) addCandidate(imp *ImportInfo, pkg *packageInfo) {
+ p.candidates = append(p.candidates, imp)
+ if existing, ok := p.knownPackages[imp.ImportPath]; ok {
+ if existing.name == "" {
+ existing.name = pkg.name
+ }
+ for export := range pkg.exports {
+ existing.exports[export] = true
+ }
+ } else {
+ p.knownPackages[imp.ImportPath] = pkg
+ }
+}
+
+// fixImports adds and removes imports from f so that all its references are
+// satisfied and there are no unused imports.
+//
+// This is declared as a variable rather than a function so goimports can
+// easily be extended by adding a file with an init function.
+var fixImports = fixImportsDefault
+
+func fixImportsDefault(fset *token.FileSet, f *ast.File, filename string, env *ProcessEnv) error {
+ fixes, err := getFixes(fset, f, filename, env)
+ if err != nil {
+ return err
+ }
+ apply(fset, f, fixes)
+ return err
+}
+
+// getFixes gets the import fixes that need to be made to f in order to fix the imports.
+// It does not modify the ast.
+func getFixes(fset *token.FileSet, f *ast.File, filename string, env *ProcessEnv) ([]*ImportFix, error) {
+ abs, err := filepath.Abs(filename)
+ if err != nil {
+ return nil, err
+ }
+ srcDir := filepath.Dir(abs)
+ if env.Logf != nil {
+ env.Logf("fixImports(filename=%q), abs=%q, srcDir=%q ...", filename, abs, srcDir)
+ }
+
+ // First pass: looking only at f, and using the naive algorithm to
+ // derive package names from import paths, see if the file is already
+ // complete. We can't add any imports yet, because we don't know
+ // if missing references are actually package vars.
+ p := &pass{fset: fset, f: f, srcDir: srcDir, env: env}
+ if fixes, done := p.load(); done {
+ return fixes, nil
+ }
+
+ otherFiles := parseOtherFiles(fset, srcDir, filename)
+
+ // Second pass: add information from other files in the same package,
+ // like their package vars and imports.
+ p.otherFiles = otherFiles
+ if fixes, done := p.load(); done {
+ return fixes, nil
+ }
+
+ // Now we can try adding imports from the stdlib.
+ p.assumeSiblingImportsValid()
+ addStdlibCandidates(p, p.missingRefs)
+ if fixes, done := p.fix(); done {
+ return fixes, nil
+ }
+
+ // Third pass: get real package names where we had previously used
+ // the naive algorithm.
+ p = &pass{fset: fset, f: f, srcDir: srcDir, env: env}
+ p.loadRealPackageNames = true
+ p.otherFiles = otherFiles
+ if fixes, done := p.load(); done {
+ return fixes, nil
+ }
+
+ if err := addStdlibCandidates(p, p.missingRefs); err != nil {
+ return nil, err
+ }
+ p.assumeSiblingImportsValid()
+ if fixes, done := p.fix(); done {
+ return fixes, nil
+ }
+
+ // Go look for candidates in $GOPATH, etc. We don't necessarily load
+ // the real exports of sibling imports, so keep assuming their contents.
+ if err := addExternalCandidates(p, p.missingRefs, filename); err != nil {
+ return nil, err
+ }
+
+ p.lastTry = true
+ fixes, _ := p.fix()
+ return fixes, nil
+}
+
+// MaxRelevance is the highest relevance, used for the standard library.
+// Chosen arbitrarily to match pre-existing gopls code.
+const MaxRelevance = 7.0
+
+// getCandidatePkgs works with the passed callback to find all acceptable packages.
+// It deduplicates by import path, and uses a cached stdlib rather than reading
+// from disk.
+func getCandidatePkgs(ctx context.Context, wrappedCallback *scanCallback, filename, filePkg string, env *ProcessEnv) error {
+ notSelf := func(p *pkg) bool {
+ return p.packageName != filePkg || p.dir != filepath.Dir(filename)
+ }
+ goenv, err := env.goEnv()
+ if err != nil {
+ return err
+ }
+
+ var mu sync.Mutex // to guard asynchronous access to dupCheck
+ dupCheck := map[string]struct{}{}
+
+ // Start off with the standard library.
+ for importPath, exports := range stdlib {
+ p := &pkg{
+ dir: filepath.Join(goenv["GOROOT"], "src", importPath),
+ importPathShort: importPath,
+ packageName: path.Base(importPath),
+ relevance: MaxRelevance,
+ }
+ dupCheck[importPath] = struct{}{}
+ if notSelf(p) && wrappedCallback.dirFound(p) && wrappedCallback.packageNameLoaded(p) {
+ wrappedCallback.exportsLoaded(p, exports)
+ }
+ }
+
+ scanFilter := &scanCallback{
+ rootFound: func(root gopathwalk.Root) bool {
+ // Exclude goroot results -- getting them is relatively expensive, not cached,
+ // and generally redundant with the in-memory version.
+ return root.Type != gopathwalk.RootGOROOT && wrappedCallback.rootFound(root)
+ },
+ dirFound: wrappedCallback.dirFound,
+ packageNameLoaded: func(pkg *pkg) bool {
+ mu.Lock()
+ defer mu.Unlock()
+ if _, ok := dupCheck[pkg.importPathShort]; ok {
+ return false
+ }
+ dupCheck[pkg.importPathShort] = struct{}{}
+ return notSelf(pkg) && wrappedCallback.packageNameLoaded(pkg)
+ },
+ exportsLoaded: func(pkg *pkg, exports []string) {
+ // If we're an x_test, load the package under test's test variant.
+ if strings.HasSuffix(filePkg, "_test") && pkg.dir == filepath.Dir(filename) {
+ var err error
+ _, exports, err = loadExportsFromFiles(ctx, env, pkg.dir, true)
+ if err != nil {
+ return
+ }
+ }
+ wrappedCallback.exportsLoaded(pkg, exports)
+ },
+ }
+ resolver, err := env.GetResolver()
+ if err != nil {
+ return err
+ }
+ return resolver.scan(ctx, scanFilter)
+}
+
+func ScoreImportPaths(ctx context.Context, env *ProcessEnv, paths []string) (map[string]float64, error) {
+ result := make(map[string]float64)
+ resolver, err := env.GetResolver()
+ if err != nil {
+ return nil, err
+ }
+ for _, path := range paths {
+ result[path] = resolver.scoreImportPath(ctx, path)
+ }
+ return result, nil
+}
+
+func PrimeCache(ctx context.Context, env *ProcessEnv) error {
+ // Fully scan the disk for directories, but don't actually read any Go files.
+ callback := &scanCallback{
+ rootFound: func(gopathwalk.Root) bool {
+ return true
+ },
+ dirFound: func(pkg *pkg) bool {
+ return false
+ },
+ packageNameLoaded: func(pkg *pkg) bool {
+ return false
+ },
+ }
+ return getCandidatePkgs(ctx, callback, "", "", env)
+}
+
+func candidateImportName(pkg *pkg) string {
+ if ImportPathToAssumedName(pkg.importPathShort) != pkg.packageName {
+ return pkg.packageName
+ }
+ return ""
+}
+
+// GetAllCandidates calls wrapped for each package whose name starts with
+// searchPrefix, and can be imported from filename with the package name filePkg.
+func GetAllCandidates(ctx context.Context, wrapped func(ImportFix), searchPrefix, filename, filePkg string, env *ProcessEnv) error {
+ callback := &scanCallback{
+ rootFound: func(gopathwalk.Root) bool {
+ return true
+ },
+ dirFound: func(pkg *pkg) bool {
+ if !canUse(filename, pkg.dir) {
+ return false
+ }
+ // Try the assumed package name first, then a simpler path match
+ // in case of packages named vN, which are not uncommon.
+ return strings.HasPrefix(ImportPathToAssumedName(pkg.importPathShort), searchPrefix) ||
+ strings.HasPrefix(path.Base(pkg.importPathShort), searchPrefix)
+ },
+ packageNameLoaded: func(pkg *pkg) bool {
+ if !strings.HasPrefix(pkg.packageName, searchPrefix) {
+ return false
+ }
+ wrapped(ImportFix{
+ StmtInfo: ImportInfo{
+ ImportPath: pkg.importPathShort,
+ Name: candidateImportName(pkg),
+ },
+ IdentName: pkg.packageName,
+ FixType: AddImport,
+ Relevance: pkg.relevance,
+ })
+ return false
+ },
+ }
+ return getCandidatePkgs(ctx, callback, filename, filePkg, env)
+}
+
+// GetImportPaths calls wrapped for each package whose import path starts with
+// searchPrefix, and can be imported from filename with the package name filePkg.
+func GetImportPaths(ctx context.Context, wrapped func(ImportFix), searchPrefix, filename, filePkg string, env *ProcessEnv) error {
+ callback := &scanCallback{
+ rootFound: func(gopathwalk.Root) bool {
+ return true
+ },
+ dirFound: func(pkg *pkg) bool {
+ if !canUse(filename, pkg.dir) {
+ return false
+ }
+ return strings.HasPrefix(pkg.importPathShort, searchPrefix)
+ },
+ packageNameLoaded: func(pkg *pkg) bool {
+ wrapped(ImportFix{
+ StmtInfo: ImportInfo{
+ ImportPath: pkg.importPathShort,
+ Name: candidateImportName(pkg),
+ },
+ IdentName: pkg.packageName,
+ FixType: AddImport,
+ Relevance: pkg.relevance,
+ })
+ return false
+ },
+ }
+ return getCandidatePkgs(ctx, callback, filename, filePkg, env)
+}
+
+// A PackageExport is a package and its exports.
+type PackageExport struct {
+ Fix *ImportFix
+ Exports []string
+}
+
+// GetPackageExports returns all known packages with name pkg and their exports.
+func GetPackageExports(ctx context.Context, wrapped func(PackageExport), searchPkg, filename, filePkg string, env *ProcessEnv) error {
+ callback := &scanCallback{
+ rootFound: func(gopathwalk.Root) bool {
+ return true
+ },
+ dirFound: func(pkg *pkg) bool {
+ return pkgIsCandidate(filename, references{searchPkg: nil}, pkg)
+ },
+ packageNameLoaded: func(pkg *pkg) bool {
+ return pkg.packageName == searchPkg
+ },
+ exportsLoaded: func(pkg *pkg, exports []string) {
+ sort.Strings(exports)
+ wrapped(PackageExport{
+ Fix: &ImportFix{
+ StmtInfo: ImportInfo{
+ ImportPath: pkg.importPathShort,
+ Name: candidateImportName(pkg),
+ },
+ IdentName: pkg.packageName,
+ FixType: AddImport,
+ Relevance: pkg.relevance,
+ },
+ Exports: exports,
+ })
+ },
+ }
+ return getCandidatePkgs(ctx, callback, filename, filePkg, env)
+}
+
+var RequiredGoEnvVars = []string{"GO111MODULE", "GOFLAGS", "GOINSECURE", "GOMOD", "GOMODCACHE", "GONOPROXY", "GONOSUMDB", "GOPATH", "GOPROXY", "GOROOT", "GOSUMDB"}
+
+// ProcessEnv contains environment variables and settings that affect the use of
+// the go command, the go/build package, etc.
+type ProcessEnv struct {
+ GocmdRunner *gocommand.Runner
+
+ BuildFlags []string
+ ModFlag string
+ ModFile string
+
+ // Env overrides the OS environment, and can be used to specify
+ // GOPROXY, GO111MODULE, etc. PATH cannot be set here, because
+ // exec.Command will not honor it.
+ // Specifying all of RequiredGoEnvVars avoids a call to `go env`.
+ Env map[string]string
+
+ WorkingDir string
+
+ // If Logf is non-nil, debug logging is enabled through this function.
+ Logf func(format string, args ...interface{})
+
+ initialized bool
+
+ resolver Resolver
+}
+
+func (e *ProcessEnv) goEnv() (map[string]string, error) {
+ if err := e.init(); err != nil {
+ return nil, err
+ }
+ return e.Env, nil
+}
+
+func (e *ProcessEnv) matchFile(dir, name string) (bool, error) {
+ bctx, err := e.buildContext()
+ if err != nil {
+ return false, err
+ }
+ return bctx.MatchFile(dir, name)
+}
+
+// CopyConfig copies the env's configuration into a new env.
+func (e *ProcessEnv) CopyConfig() *ProcessEnv {
+ copy := &ProcessEnv{
+ GocmdRunner: e.GocmdRunner,
+ initialized: e.initialized,
+ BuildFlags: e.BuildFlags,
+ Logf: e.Logf,
+ WorkingDir: e.WorkingDir,
+ resolver: nil,
+ Env: map[string]string{},
+ }
+ for k, v := range e.Env {
+ copy.Env[k] = v
+ }
+ return copy
+}
+
+func (e *ProcessEnv) init() error {
+ if e.initialized {
+ return nil
+ }
+
+ foundAllRequired := true
+ for _, k := range RequiredGoEnvVars {
+ if _, ok := e.Env[k]; !ok {
+ foundAllRequired = false
+ break
+ }
+ }
+ if foundAllRequired {
+ e.initialized = true
+ return nil
+ }
+
+ if e.Env == nil {
+ e.Env = map[string]string{}
+ }
+
+ goEnv := map[string]string{}
+ stdout, err := e.invokeGo(context.TODO(), "env", append([]string{"-json"}, RequiredGoEnvVars...)...)
+ if err != nil {
+ return err
+ }
+ if err := json.Unmarshal(stdout.Bytes(), &goEnv); err != nil {
+ return err
+ }
+ for k, v := range goEnv {
+ e.Env[k] = v
+ }
+ e.initialized = true
+ return nil
+}
+
+func (e *ProcessEnv) env() []string {
+ var env []string // the gocommand package will prepend os.Environ.
+ for k, v := range e.Env {
+ env = append(env, k+"="+v)
+ }
+ return env
+}
+
+func (e *ProcessEnv) GetResolver() (Resolver, error) {
+ if e.resolver != nil {
+ return e.resolver, nil
+ }
+ if err := e.init(); err != nil {
+ return nil, err
+ }
+ if len(e.Env["GOMOD"]) == 0 {
+ e.resolver = newGopathResolver(e)
+ return e.resolver, nil
+ }
+ e.resolver = newModuleResolver(e)
+ return e.resolver, nil
+}
+
+func (e *ProcessEnv) buildContext() (*build.Context, error) {
+ ctx := build.Default
+ goenv, err := e.goEnv()
+ if err != nil {
+ return nil, err
+ }
+ ctx.GOROOT = goenv["GOROOT"]
+ ctx.GOPATH = goenv["GOPATH"]
+
+ // As of Go 1.14, build.Context has a Dir field
+ // (see golang.org/issue/34860).
+ // Populate it only if present.
+ rc := reflect.ValueOf(&ctx).Elem()
+ dir := rc.FieldByName("Dir")
+ if dir.IsValid() && dir.Kind() == reflect.String {
+ dir.SetString(e.WorkingDir)
+ }
+
+ // Since Go 1.11, go/build.Context.Import may invoke 'go list' depending on
+ // the value in GO111MODULE in the process's environment. We always want to
+ // run in GOPATH mode when calling Import, so we need to prevent this from
+ // happening. In Go 1.16, GO111MODULE defaults to "on", so this problem comes
+ // up more frequently.
+ //
+ // HACK: setting any of the Context I/O hooks prevents Import from invoking
+ // 'go list', regardless of GO111MODULE. This is undocumented, but it's
+ // unlikely to change before GOPATH support is removed.
+ ctx.ReadDir = ioutil.ReadDir
+
+ return &ctx, nil
+}
+
+func (e *ProcessEnv) invokeGo(ctx context.Context, verb string, args ...string) (*bytes.Buffer, error) {
+ inv := gocommand.Invocation{
+ Verb: verb,
+ Args: args,
+ BuildFlags: e.BuildFlags,
+ Env: e.env(),
+ Logf: e.Logf,
+ WorkingDir: e.WorkingDir,
+ }
+ return e.GocmdRunner.Run(ctx, inv)
+}
+
+func addStdlibCandidates(pass *pass, refs references) error {
+ goenv, err := pass.env.goEnv()
+ if err != nil {
+ return err
+ }
+ add := func(pkg string) {
+ // Prevent self-imports.
+ if path.Base(pkg) == pass.f.Name.Name && filepath.Join(goenv["GOROOT"], "src", pkg) == pass.srcDir {
+ return
+ }
+ exports := copyExports(stdlib[pkg])
+ pass.addCandidate(
+ &ImportInfo{ImportPath: pkg},
+ &packageInfo{name: path.Base(pkg), exports: exports})
+ }
+ for left := range refs {
+ if left == "rand" {
+ // Make sure we try crypto/rand before math/rand.
+ add("crypto/rand")
+ add("math/rand")
+ continue
+ }
+ for importPath := range stdlib {
+ if path.Base(importPath) == left {
+ add(importPath)
+ }
+ }
+ }
+ return nil
+}
+
+// A Resolver does the build-system-specific parts of goimports.
+type Resolver interface {
+ // loadPackageNames loads the package names in importPaths.
+ loadPackageNames(importPaths []string, srcDir string) (map[string]string, error)
+ // scan works with callback to search for packages. See scanCallback for details.
+ scan(ctx context.Context, callback *scanCallback) error
+ // loadExports returns the set of exported symbols in the package at dir.
+ // loadExports may be called concurrently.
+ loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error)
+ // scoreImportPath returns the relevance for an import path.
+ scoreImportPath(ctx context.Context, path string) float64
+
+ ClearForNewScan()
+}
+
+// A scanCallback controls a call to scan and receives its results.
+// In general, minor errors will be silently discarded; a user should not
+// expect to receive a full series of calls for everything.
+type scanCallback struct {
+ // rootFound is called before scanning a new root dir. If it returns true,
+ // the root will be scanned. Returning false will not necessarily prevent
+ // directories from that root making it to dirFound.
+ rootFound func(gopathwalk.Root) bool
+ // dirFound is called when a directory is found that is possibly a Go package.
+ // pkg will be populated with everything except packageName.
+ // If it returns true, the package's name will be loaded.
+ dirFound func(pkg *pkg) bool
+ // packageNameLoaded is called when a package is found and its name is loaded.
+ // If it returns true, the package's exports will be loaded.
+ packageNameLoaded func(pkg *pkg) bool
+ // exportsLoaded is called when a package's exports have been loaded.
+ exportsLoaded func(pkg *pkg, exports []string)
+}
+
+func addExternalCandidates(pass *pass, refs references, filename string) error {
+ var mu sync.Mutex
+ found := make(map[string][]pkgDistance)
+ callback := &scanCallback{
+ rootFound: func(gopathwalk.Root) bool {
+ return true // We want everything.
+ },
+ dirFound: func(pkg *pkg) bool {
+ return pkgIsCandidate(filename, refs, pkg)
+ },
+ packageNameLoaded: func(pkg *pkg) bool {
+ if _, want := refs[pkg.packageName]; !want {
+ return false
+ }
+ if pkg.dir == pass.srcDir && pass.f.Name.Name == pkg.packageName {
+ // The candidate is in the same directory and has the
+ // same package name. Don't try to import ourselves.
+ return false
+ }
+ if !canUse(filename, pkg.dir) {
+ return false
+ }
+ mu.Lock()
+ defer mu.Unlock()
+ found[pkg.packageName] = append(found[pkg.packageName], pkgDistance{pkg, distance(pass.srcDir, pkg.dir)})
+ return false // We'll do our own loading after we sort.
+ },
+ }
+ resolver, err := pass.env.GetResolver()
+ if err != nil {
+ return err
+ }
+ if err = resolver.scan(context.Background(), callback); err != nil {
+ return err
+ }
+
+ // Search for imports matching potential package references.
+ type result struct {
+ imp *ImportInfo
+ pkg *packageInfo
+ }
+ results := make(chan result, len(refs))
+
+ ctx, cancel := context.WithCancel(context.TODO())
+ var wg sync.WaitGroup
+ defer func() {
+ cancel()
+ wg.Wait()
+ }()
+ var (
+ firstErr error
+ firstErrOnce sync.Once
+ )
+ for pkgName, symbols := range refs {
+ wg.Add(1)
+ go func(pkgName string, symbols map[string]bool) {
+ defer wg.Done()
+
+ found, err := findImport(ctx, pass, found[pkgName], pkgName, symbols, filename)
+
+ if err != nil {
+ firstErrOnce.Do(func() {
+ firstErr = err
+ cancel()
+ })
+ return
+ }
+
+ if found == nil {
+ return // No matching package.
+ }
+
+ imp := &ImportInfo{
+ ImportPath: found.importPathShort,
+ }
+
+ pkg := &packageInfo{
+ name: pkgName,
+ exports: symbols,
+ }
+ results <- result{imp, pkg}
+ }(pkgName, symbols)
+ }
+ go func() {
+ wg.Wait()
+ close(results)
+ }()
+
+ for result := range results {
+ pass.addCandidate(result.imp, result.pkg)
+ }
+ return firstErr
+}
+
+// notIdentifier reports whether ch is an invalid identifier character.
+func notIdentifier(ch rune) bool {
+ return !('a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' ||
+ '0' <= ch && ch <= '9' ||
+ ch == '_' ||
+ ch >= utf8.RuneSelf && (unicode.IsLetter(ch) || unicode.IsDigit(ch)))
+}
+
+// ImportPathToAssumedName returns the assumed package name of an import path.
+// It does this using only string parsing of the import path.
+// It picks the last element of the path that does not look like a major
+// version, and then picks the valid identifier off the start of that element.
+// It is used to determine if a local rename should be added to an import for
+// clarity.
+// This function could be moved to a standard package and exported if we want
+// for use in other tools.
+func ImportPathToAssumedName(importPath string) string {
+ base := path.Base(importPath)
+ if strings.HasPrefix(base, "v") {
+ if _, err := strconv.Atoi(base[1:]); err == nil {
+ dir := path.Dir(importPath)
+ if dir != "." {
+ base = path.Base(dir)
+ }
+ }
+ }
+ base = strings.TrimPrefix(base, "go-")
+ if i := strings.IndexFunc(base, notIdentifier); i >= 0 {
+ base = base[:i]
+ }
+ return base
+}
+
+// gopathResolver implements resolver for GOPATH workspaces.
+type gopathResolver struct {
+ env *ProcessEnv
+ walked bool
+ cache *dirInfoCache
+ scanSema chan struct{} // scanSema prevents concurrent scans.
+}
+
+func newGopathResolver(env *ProcessEnv) *gopathResolver {
+ r := &gopathResolver{
+ env: env,
+ cache: &dirInfoCache{
+ dirs: map[string]*directoryPackageInfo{},
+ listeners: map[*int]cacheListener{},
+ },
+ scanSema: make(chan struct{}, 1),
+ }
+ r.scanSema <- struct{}{}
+ return r
+}
+
+func (r *gopathResolver) ClearForNewScan() {
+ <-r.scanSema
+ r.cache = &dirInfoCache{
+ dirs: map[string]*directoryPackageInfo{},
+ listeners: map[*int]cacheListener{},
+ }
+ r.walked = false
+ r.scanSema <- struct{}{}
+}
+
+func (r *gopathResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
+ names := map[string]string{}
+ bctx, err := r.env.buildContext()
+ if err != nil {
+ return nil, err
+ }
+ for _, path := range importPaths {
+ names[path] = importPathToName(bctx, path, srcDir)
+ }
+ return names, nil
+}
+
+// importPathToName finds out the actual package name, as declared in its .go files.
+func importPathToName(bctx *build.Context, importPath, srcDir string) string {
+ // Fast path for standard library without going to disk.
+ if _, ok := stdlib[importPath]; ok {
+ return path.Base(importPath) // stdlib packages always match their paths.
+ }
+
+ buildPkg, err := bctx.Import(importPath, srcDir, build.FindOnly)
+ if err != nil {
+ return ""
+ }
+ pkgName, err := packageDirToName(buildPkg.Dir)
+ if err != nil {
+ return ""
+ }
+ return pkgName
+}
+
+// packageDirToName is a faster version of build.Import if
+// the only thing desired is the package name. Given a directory,
+// packageDirToName then only parses one file in the package,
+// trusting that the files in the directory are consistent.
+func packageDirToName(dir string) (packageName string, err error) {
+ d, err := os.Open(dir)
+ if err != nil {
+ return "", err
+ }
+ names, err := d.Readdirnames(-1)
+ d.Close()
+ if err != nil {
+ return "", err
+ }
+ sort.Strings(names) // to have predictable behavior
+ var lastErr error
+ var nfile int
+ for _, name := range names {
+ if !strings.HasSuffix(name, ".go") {
+ continue
+ }
+ if strings.HasSuffix(name, "_test.go") {
+ continue
+ }
+ nfile++
+ fullFile := filepath.Join(dir, name)
+
+ fset := token.NewFileSet()
+ f, err := parser.ParseFile(fset, fullFile, nil, parser.PackageClauseOnly)
+ if err != nil {
+ lastErr = err
+ continue
+ }
+ pkgName := f.Name.Name
+ if pkgName == "documentation" {
+ // Special case from go/build.ImportDir, not
+ // handled by ctx.MatchFile.
+ continue
+ }
+ if pkgName == "main" {
+ // Also skip package main, assuming it's a +build ignore generator or example.
+ // Since you can't import a package main anyway, there's no harm here.
+ continue
+ }
+ return pkgName, nil
+ }
+ if lastErr != nil {
+ return "", lastErr
+ }
+ return "", fmt.Errorf("no importable package found in %d Go files", nfile)
+}
+
+type pkg struct {
+ dir string // absolute file path to pkg directory ("/usr/lib/go/src/net/http")
+ importPathShort string // vendorless import path ("net/http", "a/b")
+ packageName string // package name loaded from source if requested
+ relevance float64 // a weakly-defined score of how relevant a package is. 0 is most relevant.
+}
+
+type pkgDistance struct {
+ pkg *pkg
+ distance int // relative distance to target
+}
+
+// byDistanceOrImportPathShortLength sorts by relative distance breaking ties
+// on the short import path length and then the import string itself.
+type byDistanceOrImportPathShortLength []pkgDistance
+
+func (s byDistanceOrImportPathShortLength) Len() int { return len(s) }
+func (s byDistanceOrImportPathShortLength) Less(i, j int) bool {
+ di, dj := s[i].distance, s[j].distance
+ if di == -1 {
+ return false
+ }
+ if dj == -1 {
+ return true
+ }
+ if di != dj {
+ return di < dj
+ }
+
+ vi, vj := s[i].pkg.importPathShort, s[j].pkg.importPathShort
+ if len(vi) != len(vj) {
+ return len(vi) < len(vj)
+ }
+ return vi < vj
+}
+func (s byDistanceOrImportPathShortLength) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+
+func distance(basepath, targetpath string) int {
+ p, err := filepath.Rel(basepath, targetpath)
+ if err != nil {
+ return -1
+ }
+ if p == "." {
+ return 0
+ }
+ return strings.Count(p, string(filepath.Separator)) + 1
+}
+
+func (r *gopathResolver) scan(ctx context.Context, callback *scanCallback) error {
+ add := func(root gopathwalk.Root, dir string) {
+ // We assume cached directories have not changed. We can skip them and their
+ // children.
+ if _, ok := r.cache.Load(dir); ok {
+ return
+ }
+
+ importpath := filepath.ToSlash(dir[len(root.Path)+len("/"):])
+ info := directoryPackageInfo{
+ status: directoryScanned,
+ dir: dir,
+ rootType: root.Type,
+ nonCanonicalImportPath: VendorlessPath(importpath),
+ }
+ r.cache.Store(dir, info)
+ }
+ processDir := func(info directoryPackageInfo) {
+ // Skip this directory if we were not able to get the package information successfully.
+ if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
+ return
+ }
+
+ p := &pkg{
+ importPathShort: info.nonCanonicalImportPath,
+ dir: info.dir,
+ relevance: MaxRelevance - 1,
+ }
+ if info.rootType == gopathwalk.RootGOROOT {
+ p.relevance = MaxRelevance
+ }
+
+ if !callback.dirFound(p) {
+ return
+ }
+ var err error
+ p.packageName, err = r.cache.CachePackageName(info)
+ if err != nil {
+ return
+ }
+
+ if !callback.packageNameLoaded(p) {
+ return
+ }
+ if _, exports, err := r.loadExports(ctx, p, false); err == nil {
+ callback.exportsLoaded(p, exports)
+ }
+ }
+ stop := r.cache.ScanAndListen(ctx, processDir)
+ defer stop()
+
+ goenv, err := r.env.goEnv()
+ if err != nil {
+ return err
+ }
+ var roots []gopathwalk.Root
+ roots = append(roots, gopathwalk.Root{filepath.Join(goenv["GOROOT"], "src"), gopathwalk.RootGOROOT})
+ for _, p := range filepath.SplitList(goenv["GOPATH"]) {
+ roots = append(roots, gopathwalk.Root{filepath.Join(p, "src"), gopathwalk.RootGOPATH})
+ }
+ // The callback is not necessarily safe to use in the goroutine below. Process roots eagerly.
+ roots = filterRoots(roots, callback.rootFound)
+ // We can't cancel walks, because we need them to finish to have a usable
+ // cache. Instead, run them in a separate goroutine and detach.
+ scanDone := make(chan struct{})
+ go func() {
+ select {
+ case <-ctx.Done():
+ return
+ case <-r.scanSema:
+ }
+ defer func() { r.scanSema <- struct{}{} }()
+ gopathwalk.Walk(roots, add, gopathwalk.Options{Logf: r.env.Logf, ModulesEnabled: false})
+ close(scanDone)
+ }()
+ select {
+ case <-ctx.Done():
+ case <-scanDone:
+ }
+ return nil
+}
+
+func (r *gopathResolver) scoreImportPath(ctx context.Context, path string) float64 {
+ if _, ok := stdlib[path]; ok {
+ return MaxRelevance
+ }
+ return MaxRelevance - 1
+}
+
+func filterRoots(roots []gopathwalk.Root, include func(gopathwalk.Root) bool) []gopathwalk.Root {
+ var result []gopathwalk.Root
+ for _, root := range roots {
+ if !include(root) {
+ continue
+ }
+ result = append(result, root)
+ }
+ return result
+}
+
+func (r *gopathResolver) loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error) {
+ if info, ok := r.cache.Load(pkg.dir); ok && !includeTest {
+ return r.cache.CacheExports(ctx, r.env, info)
+ }
+ return loadExportsFromFiles(ctx, r.env, pkg.dir, includeTest)
+}
+
+// VendorlessPath returns the devendorized version of the import path ipath.
+// For example, VendorlessPath("foo/bar/vendor/a/b") returns "a/b".
+func VendorlessPath(ipath string) string {
+ // Devendorize for use in import statement.
+ if i := strings.LastIndex(ipath, "/vendor/"); i >= 0 {
+ return ipath[i+len("/vendor/"):]
+ }
+ if strings.HasPrefix(ipath, "vendor/") {
+ return ipath[len("vendor/"):]
+ }
+ return ipath
+}
+
+func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string, includeTest bool) (string, []string, error) {
+ // Look for non-test, buildable .go files which could provide exports.
+ all, err := ioutil.ReadDir(dir)
+ if err != nil {
+ return "", nil, err
+ }
+ var files []os.FileInfo
+ for _, fi := range all {
+ name := fi.Name()
+ if !strings.HasSuffix(name, ".go") || (!includeTest && strings.HasSuffix(name, "_test.go")) {
+ continue
+ }
+ match, err := env.matchFile(dir, fi.Name())
+ if err != nil || !match {
+ continue
+ }
+ files = append(files, fi)
+ }
+
+ if len(files) == 0 {
+ return "", nil, fmt.Errorf("dir %v contains no buildable, non-test .go files", dir)
+ }
+
+ var pkgName string
+ var exports []string
+ fset := token.NewFileSet()
+ for _, fi := range files {
+ select {
+ case <-ctx.Done():
+ return "", nil, ctx.Err()
+ default:
+ }
+
+ fullFile := filepath.Join(dir, fi.Name())
+ f, err := parser.ParseFile(fset, fullFile, nil, 0)
+ if err != nil {
+ if env.Logf != nil {
+ env.Logf("error parsing %v: %v", fullFile, err)
+ }
+ continue
+ }
+ if f.Name.Name == "documentation" {
+ // Special case from go/build.ImportDir, not
+ // handled by MatchFile above.
+ continue
+ }
+ if includeTest && strings.HasSuffix(f.Name.Name, "_test") {
+ // x_test package. We want internal test files only.
+ continue
+ }
+ pkgName = f.Name.Name
+ for name := range f.Scope.Objects {
+ if ast.IsExported(name) {
+ exports = append(exports, name)
+ }
+ }
+ }
+
+ if env.Logf != nil {
+ sortedExports := append([]string(nil), exports...)
+ sort.Strings(sortedExports)
+ env.Logf("loaded exports in dir %v (package %v): %v", dir, pkgName, strings.Join(sortedExports, ", "))
+ }
+ return pkgName, exports, nil
+}
+
+// findImport searches for a package with the given symbols.
+// If no package is found, findImport returns ("", false, nil)
+func findImport(ctx context.Context, pass *pass, candidates []pkgDistance, pkgName string, symbols map[string]bool, filename string) (*pkg, error) {
+ // Sort the candidates by their import package length,
+ // assuming that shorter package names are better than long
+ // ones. Note that this sorts by the de-vendored name, so
+ // there's no "penalty" for vendoring.
+ sort.Sort(byDistanceOrImportPathShortLength(candidates))
+ if pass.env.Logf != nil {
+ for i, c := range candidates {
+ pass.env.Logf("%s candidate %d/%d: %v in %v", pkgName, i+1, len(candidates), c.pkg.importPathShort, c.pkg.dir)
+ }
+ }
+ resolver, err := pass.env.GetResolver()
+ if err != nil {
+ return nil, err
+ }
+
+ // Collect exports for packages with matching names.
+ rescv := make([]chan *pkg, len(candidates))
+ for i := range candidates {
+ rescv[i] = make(chan *pkg, 1)
+ }
+ const maxConcurrentPackageImport = 4
+ loadExportsSem := make(chan struct{}, maxConcurrentPackageImport)
+
+ ctx, cancel := context.WithCancel(ctx)
+ var wg sync.WaitGroup
+ defer func() {
+ cancel()
+ wg.Wait()
+ }()
+
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ for i, c := range candidates {
+ select {
+ case loadExportsSem <- struct{}{}:
+ case <-ctx.Done():
+ return
+ }
+
+ wg.Add(1)
+ go func(c pkgDistance, resc chan<- *pkg) {
+ defer func() {
+ <-loadExportsSem
+ wg.Done()
+ }()
+
+ if pass.env.Logf != nil {
+ pass.env.Logf("loading exports in dir %s (seeking package %s)", c.pkg.dir, pkgName)
+ }
+ // If we're an x_test, load the package under test's test variant.
+ includeTest := strings.HasSuffix(pass.f.Name.Name, "_test") && c.pkg.dir == pass.srcDir
+ _, exports, err := resolver.loadExports(ctx, c.pkg, includeTest)
+ if err != nil {
+ if pass.env.Logf != nil {
+ pass.env.Logf("loading exports in dir %s (seeking package %s): %v", c.pkg.dir, pkgName, err)
+ }
+ resc <- nil
+ return
+ }
+
+ exportsMap := make(map[string]bool, len(exports))
+ for _, sym := range exports {
+ exportsMap[sym] = true
+ }
+
+ // If it doesn't have the right
+ // symbols, send nil to mean no match.
+ for symbol := range symbols {
+ if !exportsMap[symbol] {
+ resc <- nil
+ return
+ }
+ }
+ resc <- c.pkg
+ }(c, rescv[i])
+ }
+ }()
+
+ for _, resc := range rescv {
+ pkg := <-resc
+ if pkg == nil {
+ continue
+ }
+ return pkg, nil
+ }
+ return nil, nil
+}
+
+// pkgIsCandidate reports whether pkg is a candidate for satisfying the
+// finding which package pkgIdent in the file named by filename is trying
+// to refer to.
+//
+// This check is purely lexical and is meant to be as fast as possible
+// because it's run over all $GOPATH directories to filter out poor
+// candidates in order to limit the CPU and I/O later parsing the
+// exports in candidate packages.
+//
+// filename is the file being formatted.
+// pkgIdent is the package being searched for, like "client" (if
+// searching for "client.New")
+func pkgIsCandidate(filename string, refs references, pkg *pkg) bool {
+ // Check "internal" and "vendor" visibility:
+ if !canUse(filename, pkg.dir) {
+ return false
+ }
+
+ // Speed optimization to minimize disk I/O:
+ // the last two components on disk must contain the
+ // package name somewhere.
+ //
+ // This permits mismatch naming like directory
+ // "go-foo" being package "foo", or "pkg.v3" being "pkg",
+ // or directory "google.golang.org/api/cloudbilling/v1"
+ // being package "cloudbilling", but doesn't
+ // permit a directory "foo" to be package
+ // "bar", which is strongly discouraged
+ // anyway. There's no reason goimports needs
+ // to be slow just to accommodate that.
+ for pkgIdent := range refs {
+ lastTwo := lastTwoComponents(pkg.importPathShort)
+ if strings.Contains(lastTwo, pkgIdent) {
+ return true
+ }
+ if hasHyphenOrUpperASCII(lastTwo) && !hasHyphenOrUpperASCII(pkgIdent) {
+ lastTwo = lowerASCIIAndRemoveHyphen(lastTwo)
+ if strings.Contains(lastTwo, pkgIdent) {
+ return true
+ }
+ }
+ }
+ return false
+}
+
+func hasHyphenOrUpperASCII(s string) bool {
+ for i := 0; i < len(s); i++ {
+ b := s[i]
+ if b == '-' || ('A' <= b && b <= 'Z') {
+ return true
+ }
+ }
+ return false
+}
+
+func lowerASCIIAndRemoveHyphen(s string) (ret string) {
+ buf := make([]byte, 0, len(s))
+ for i := 0; i < len(s); i++ {
+ b := s[i]
+ switch {
+ case b == '-':
+ continue
+ case 'A' <= b && b <= 'Z':
+ buf = append(buf, b+('a'-'A'))
+ default:
+ buf = append(buf, b)
+ }
+ }
+ return string(buf)
+}
+
+// canUse reports whether the package in dir is usable from filename,
+// respecting the Go "internal" and "vendor" visibility rules.
+func canUse(filename, dir string) bool {
+ // Fast path check, before any allocations. If it doesn't contain vendor
+ // or internal, it's not tricky:
+ // Note that this can false-negative on directories like "notinternal",
+ // but we check it correctly below. This is just a fast path.
+ if !strings.Contains(dir, "vendor") && !strings.Contains(dir, "internal") {
+ return true
+ }
+
+ dirSlash := filepath.ToSlash(dir)
+ if !strings.Contains(dirSlash, "/vendor/") && !strings.Contains(dirSlash, "/internal/") && !strings.HasSuffix(dirSlash, "/internal") {
+ return true
+ }
+ // Vendor or internal directory only visible from children of parent.
+ // That means the path from the current directory to the target directory
+ // can contain ../vendor or ../internal but not ../foo/vendor or ../foo/internal
+ // or bar/vendor or bar/internal.
+ // After stripping all the leading ../, the only okay place to see vendor or internal
+ // is at the very beginning of the path.
+ absfile, err := filepath.Abs(filename)
+ if err != nil {
+ return false
+ }
+ absdir, err := filepath.Abs(dir)
+ if err != nil {
+ return false
+ }
+ rel, err := filepath.Rel(absfile, absdir)
+ if err != nil {
+ return false
+ }
+ relSlash := filepath.ToSlash(rel)
+ if i := strings.LastIndex(relSlash, "../"); i >= 0 {
+ relSlash = relSlash[i+len("../"):]
+ }
+ return !strings.Contains(relSlash, "/vendor/") && !strings.Contains(relSlash, "/internal/") && !strings.HasSuffix(relSlash, "/internal")
+}
+
+// lastTwoComponents returns at most the last two path components
+// of v, using either / or \ as the path separator.
+func lastTwoComponents(v string) string {
+ nslash := 0
+ for i := len(v) - 1; i >= 0; i-- {
+ if v[i] == '/' || v[i] == '\\' {
+ nslash++
+ if nslash == 2 {
+ return v[i:]
+ }
+ }
+ }
+ return v
+}
+
+type visitFn func(node ast.Node) ast.Visitor
+
+func (fn visitFn) Visit(node ast.Node) ast.Visitor {
+ return fn(node)
+}
+
+func copyExports(pkg []string) map[string]bool {
+ m := make(map[string]bool, len(pkg))
+ for _, v := range pkg {
+ m[v] = true
+ }
+ return m
+}
projects / dotfiles / .git / blobdiff